The BOM say their temperature records are high quality. An independent audit team has just produced a report showing that as many as 85 -95% of all Australian sites in the pre-Celsius era (before 1972) did not comply with the BOM’s own stipulations. The audit shows 20-30% of all the measurements back then were rounded or possibly truncated. Even modern electronic equipment was at times, so faulty and unmonitored that one station rounded all the readings for nearly 10 years! These sloppy errors may have created an artificial warming trend. The BOM are issuing pronouncements of trends to two decimal places like this one in the BOM’s Annual Climate Summary 2011 of “0.52 °C above average” yet relying on patchy data that did not meet its own compliance standards around half the time. It’s doubtful they can justify one decimal place, let alone two?

We need a professional audit.

A team of independent engineers, scientists, statisticians and data analysts (brought together by the joannenova blog) has been going through the Australia Bureau of Meteorology records (BOM). They’ve audited some 8.5 million daily observations across 237 High Quality and other close sites in Australia. Shockingly, while the BOM calls their database “High Quality” and instructed observers before 1972 to record in tenths of a degree Fahrenheit, the auditors started finding sites with long stretches of records where the weather suspiciously rose and fell only in Fahrenheit quanta, like 72.0, 73.0, 72.0, 71.0, 73.0, 72.0. After 1972, the BOM went metric, and oddly, so did parts of the Australian climate. Numerous sites started warming and cooling in pure Celsius integers.

The bottom line:

The BOM records need a thorough independent audit.

It’s possible that a significant part of the 20th Century Australian warming trend may have come from something as banal as sloppy observers truncating records in Fahrenheit prior to 1972.

Many High Quality sites are not high quality and ought to be deleted from the trends.

Even current electronic equipment is faulty, and the BOM is not checking its own records.

Even climate scientists admit that truncation of Fahrenheit temperatures would cause an artificial warming effect.

The Audit Team identifies a suspicious problem

It was the sharp eye of Chris Gillham who noticed the first long string of continuous whole numbers in a site record. I wondered if it was faulty equipment and thus if other sites were affected, so people started looking, and suspicious stretches started turning up everywhere. The audit team were astonished at how common the problem was. Ian Hill and Ed Thurstan developed software to search the mountain of data and discovered that while temperatures of .0 degrees ought to have been 10% of all the measurements, some 20 – 30% of the entire BOM database was recorded as whole number, or “.0″.

Fahrenheit era observations (prior to 1972) have even higher proportions of .0 than those of the Celsius era. Note the strange peaks at 0.1 and 0.9? Those are likely due to converting raw F to C and back.